.concent {
    width: 1200px;
    margin: 0 auto;
}

/* 源码大数据头部 */
header {
    display: flex;
    border-bottom: 1px solid skyblue;
    margin-bottom: 50px;

}

header .nav {
    padding-top: 20px;
    padding-left: 20px;

}

header .nav-1 {
    display: flex;
    justify-content: center;
    margin-left: 66px;
}

header .nav-1 li {
    margin: 0 10px;
    height: 66px;
    line-height: 66px;
}

header .nav-1 li:nth-child(2) {
    border-bottom: 1px solid skyblue;
    color: skyblue;
}

header .nav-2 {
    display: flex;
    align-items: center;
}

header .nav-2 li:nth-child(1) {
    border-radius: 13px;
    border: 1px solid;
    width: 60px;
    height: 24px;
    text-align: center;
    margin-right: 10px;
    font-size: 10px;
    line-height: 24px;
    color: #d1d1d1;
}

header .nav-2 li:nth-child(1) a {
    color: black;
}

header .nav-2 li:nth-child(2) {
    border-radius: 13px;
    border: 1px solid;
    width: 77px;
    height: 25px;
    text-align: center;
    margin-right: 40px;
    font-size: 10px;
    line-height: 25px;
    background: orange;
    color: white;
}

header .nav-2 li:nth-child(2) a {
    color: white;
}

/* 动态图片 */